Thus... dark matter?
Whereas he's proposing regular (dark as in color) matter
Wouldn't that kind of matter be easily detectable because it would block EM radiation, including visible light?
Edit! Wow really feeling the love on this comment
What I mean is dark matter is different from matter we just can't detect, it's matter that should be there but we can't seem to find it
It only interacts with other matter through gravity.
Now, we can detect gravity, but only for fairly big and stationary objects. If DM is tiny particles travelling fast, we can only detect aggregate effects on galaxy level.
There's a difference between matter that's there which we can't detect as opposed to matter which isn't there which we can oh geez